Steam operated horn



Jan. 6, 1948.

K. V. OZOLS STEAM OPERATED HORN Filed Nov. 10,- 1944 4 Sheets-Sheet 1Jan. 6, 1948. K. v. OZOLS STEAM OPERATED HORN Filed Nov. 10; 19:14

4 Sheets-Sheet 2 I. [NV/1%OR.

Jan. 6, 1948. K, v QZOLS I 2,434,175

STEAM OPERATED HORN Filed NOV. 10, 1944 4 Sheets-Sheet 3 FIG.4

IN VN TOR.

Jan. 6, 1948. K. v. OZOLS 2,434,175

STEAM OPERATED HORN Filed Nov. 10, 1944 4 Sheets-Sheet 4 Fla. 6

' INVENTOR.

Patented Jan; 6, 1948 A UNITED STATES PATENT OFFICE- my. canal-commit.Application November 10, 1944. Serlal'hlo. 582,893

1 The invention relates to sound producing devices, for instance hornsfor'fog si naling, for code signaling'or position locating and similarIn devices of this type the sound is frequently produced by rapidsuccessive blasts of pressure medium; these blasts are created by acircumferentially perforated sleeve or piston oscillated in a likewiseperforated cylinder; the osciliating sleeve interrupts the passage ofthe pressure medium which enters the inner space of the cylinder throughthe perforations so that a series of consecutive quick impulses of thepressure medium is produced which upon discharge from the cylinder intoa resonator create corresponding sound waves.

The main disadvantage of the hitherto known sound producing devices ofthis type consists therein that their sound intensity is poor, which ismainly due to the fact that they are operated with a single soundproducing source; therefore, the amplitude of the created sound waves isrestricted and especially the low frequency range is limited.

It is the primary object of the invention to devise a sound producingdevice which is adapted to produce an unusually strong sound intensityand an unlimited frequency range.

It is another object of the invention to create for a given energy orpressure medium input a maximum sound wave amplitude.

order to produce a maximum sound intensity for 35 a given energy input,for instance a given quan- 0 Claims. (01. 110-141) 2. The periodicbiastsof anoperating pressure medium emitted through the slots of the pistonoscillatingly displaced within a'slotted cylinder;

3. The combination ofa lip and of a resonance chamber into which thepressure medium blasts are mitted; these blasts strike the edge or lipprovided at the inside end of the resonator or resonance chamber, thussetting up vibrations which are synchronized with the naturalfrequencyof the chamber. The length of this chamber and thereby of thecolumn of the operating medium determines the frequency of the soundwaves by forcing the blasts to vibrate synchronously with this column.The frequency of the periodic blasts of the operating medium produced bythe vibrating piston is in this manner maintained in phase with thenatural frequency of the resonating chamber, whereby the sound volume isreinforced accordingly. i

Some of the above soundproducing elements are, as previously stated,known as such. The invention 'is based on the adjusted combined effectof all the sound producing elements herein described.

25 The sound amplitude is further increased by the air volumedisplacements resulting from the oscillation of the piston creatingperiodic air pressure variations in the resonance chamber and by theblasts of the pressure medium which so in turn is additionally amplifiedby the passage tity of pressure medium, it is necessary to increase thenumber' of the sound producing ele- I. The periodic displacement of anair volume resulting from the movement of an oscillating piston, wherebyperiodic air pressure variations are created in the horn;

through the horn. V

The sound producing device forming th subiect matter of my invention isillustrated by way of example in the attached drawings of which Fig. 1is a sectional elevation of the same in its initial operating position,

Fig. 2 is a sectional elevation in a second operating position,

Fig. 3 is a sectionahelevation on line 3-4 of Referring particularly tothe ngurcs, 1 is a so cylinder or Jacket which is closed at its one end;

the cylinder is provided with circumferential slots 2a, 2b; the endportion I of cylinder I has a reduced wall thickness to effect a.turbu1ence-free passage of the operating medium. A piston 4uwhichiscloscdattbeoneendoppositetothe 3clcsedendofcylinderlismountcdthereinfor reciprocative displacement;piston 4 is provided -l; the shaft protrudes into cage ll carried bypiston 4; cage II is provided with longitudinal slots If; itaccommodates a spring l4 which abuts againsthead If fastened to shaft IIand the inner wall of cage II; a second spring is is located on rod orshaft it between cylinder l and cage II. A circumferential channel itsurrounds cylinder I; a supply tube II for the pressure medium isattached to casing t; the pressure medium entering through tube l'lpasses through xreemi'erential channel it and slots 2a, to into :nnerchamber it formed by cylinder l and piston 4.

An outer horn is which preferably has a parabolic form is attached tocasing 4; an insert or inner horn 20 having the same form as outer hornis is concentrically located in the latter; a resonating chamber fl iscreated by the two horns; this chamber is shown as being closed, but itmay be left open. V

The inside end of the inner horn 20 is shaped to form a vibrator lip 22.

The operation of the device is as follows:

A suitable operating medium, for instance,

steam or compressed air, is supplied through channel I'l into acircumferential channel It, and from there through slots in and in intochamber l8. Fig. 1.

By the pressure thus created in the closed chamber the piston 4 isforced in its outer operating position, shown in Fig. 2; spring I4 iscompressed thereby.

As soon as this position is reached and a connection is produced throughslots 5b and 2b between chamber l8 and the atmosphere, the pressure isreduced and the compression spring [4 forces piston 4 back in its formerposition; hereupon the operating medium is again supplied to chamber l4and forces the sleeve in its outer position.

In this manner a rapid oscillation of the piston is maintained duringthe supply of the pressure medium and a longitudinal sound wave iscreated in the resonating chamber and in the throat Ha of horn It.

The jets of the operating medium which escape through slots lb, 2b passthrough circumferential passage 23 located between reduced end 3 ofcylinder I and easing I. The Jets hit upon the edge of lip 22 and areset into rapid vibrations in the manner which is known from the blowingof a whistle. #1

The operating medium at the same time passes into the circumferentialresonator chamber II where it creates stationary sound waves.

For the same reason of maintaining the various sound creating elementsin phase the natural frequency of the compression spring I4 shouldcoincide with the operating frequency of the horn; this is, forinstance, achieved by adjusting nut 24 and lock nut 25 which is held byset screw 28 to avoid its loosening by the vibrations of piston 4;spring I 5 prevents undesired excessive displacement of piston 4.

By regulating the pressure supply of the operating medium in accordancewith the length of 4 thehorn,theoscillationfrequeneyproducedby theoscillating piston is synchronised with the stationary waves produced inchamber II.

Inordertoregulatetheii'owrateofths atingmediumintochamber lathesiaeslotopeningsmaybevariedbyaxial mentofthe piston4. Thistmaybeeifectedbyinsertionoi'asuitabletcolinalotl ofshaft ll.Theshaftisthensecuredbyaet screw it and prevented from further axialrotation.

The steam Jacket I into which steam is supplied through pipe It preventsfreezing of the working parts of the horn.

Fig. 6 illustrates the summation of the various above describedindividual wave amplitudes in accordance with the invention.

Horizontal line, or ordinate of time, x-xv indicates the center line ofthe sound wave amplitude summarizing system.

Vertical lines or abscissae of pressure, Oo-Yo, O:uYa: and oX-Y)\ arethe center lines of the summarized wave amplitudes. Iii-00 denominatesthe wave amplitude produced by the oscillating displacement of piston 4;Ila-O0 results from the summation of amplitude h]. and of the amplitudecreated by the periodic blasts of the operating pressure medium expelledthrough the slots of piston 4;hs-Oo signifies the total sum of the threesound amplitudes produced in the horn and is obtained by adding soundamplitude ha-OO to the amplitude produced by the sympathetic vibrationsof the jet of the operating medium striking against lip 22,

It is to be understood that the construction of the horn, as describedabove and illustrated in the drawings, may be varied without departingfrom the invention.

1 claim:

1. A sound producing device comprising -a cylinder closed at its oneend, a hollow piston in said cylinder, said piston being closed at theend oppo site of the closed end of said cylinder, an inner chamberformed by said cylinder and said piston, a group of slots in thecontacting walls of said cylinder and said piston, means to admit apressure medium through said slots into said chamber and to displacesaid piston from its one end position into a second end position. asecond group of slots in said contacting walls so arranged as to connectsaid chamber in the second end position of the piston with theatmosphere and to simultaneously interrupt the admission of the pressuremedium through said first group of slots, a compression spring to returnsaid piston into its first operating position and to reestablish theconnection with said pressure medium to thereby produce a periodicreciprocation of said piston in said cylinder, periodic air pressurevariations creating sound waves and periodic pressure blastsv producingsound waves, a resonating chamber adjacent to said cylinder and a lipintegral with said resonating chamber, means to pas the periodic blastsof said pressure medium onto said lip and into said resonating chamberto produce thereby vibrations of the pressure medium creating soundwaves and to summarize said various sound waves.

2. In a sound producing device according to claim 1 means for varyingthe natural frequency of the compression spring in accordance with thelength of the resonating chamber.

3. A soimd producing device comprising a cylinder closed at its one end,a horn attached to said cylinder, a closed resonating chambercircumferentially surrounding said horn, a hollow piston in saidcylinder, said piston being closed at the end opposite of the closed endof said cylinder, a closed chamber formed by said cylinder and saidpiston, means to reciprocate said piston in said cylinder and to produceby the vibrating action of the closed end of the piston periodicpressure variations in said horn creating sound waves, means to emit bythe reciprocation of said piston, periodic blasts of a pressure mediumfrom said closed chamber into said closed resonating chamber and tothereby create stationary rebounding sound waves and means to conductsaid rebounding sound wave into the path of the closed end of saidreciprocating piston to produce in'said horn a corresponding soundaugmentation.

4. In a sound producing device according to claim 3, means forsynchronizing the frequencies of the various produced sound waves, saidmeans including a device to adjust the number of successivereciprocations of the piston.

5. A sound producing device comprising a cylinder closed at its one end,a horn attached to said cylinder, a closed resonating chambercircumferentially surrounding said horn, a hollow piston in saidcylinder, said piston being closed at the end opposite of the closed endof said piston, a closed chamber formed by said cylinder and saidpiston, means to reciprocate said piston in said cylinder and to produceby the vibrations in said horn thereby creating sound waves, means toconnect said chamber alternatively with a high and a low pressure mediumto create periodic pressure blasts producing sound waves,

means to emit said periodic blasts from said 35 6 waves in said soundproducing device and to thereby augment the sound intensity.

6. A sound producing device comprising a cylinder closed at its one end,a horn attached to said cylinder, a closed resonating chambercircumferentially surrounding" said horn, a hollow piston in saidcylinder,"said piston being closed at the end opposite of the closed endof vsaid cylinder, a closed chamber formed by said cylinder and saidpiston, a fluid pressure medium and a spring to reciprocate said pistonin said cylinder and to produce by the vibrating action of the closedend of the piston periodic pressure variations in said horn therebycreating sound waves, means to emit by the reciprocation of said pistonfrom said closed chamber periodic blasts of a pressure medium into saidclosed resonating chamber and to thereby create stationary reboundingsound waves and means to conduct said rebounding sound waves into thepath of the closed end of said reciprocating piston to produce in saidhorn a corresponding sound augmentation.

KARLIS V. OZOLS.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 606,668 Hunter July 5, 18981,844,226 Northey Feb. 9, 1932 1,624,873 Landis Apr. 12, 1927 1,289,065Wolfl Dec. 24, 1918 1,522,095 Booty Jan. 6, 1925 1,486,650 Foley Mar.11, 1924 2,019,596 Broden Nov. 5, 1935 1,653,119 Perrin et a1. Dec. 20,1927

